This invention relates to automotive body framing systems, for example, of the general type disclosed in U.S. Pat. No. 5,143,270, U.S. Pat. No. 5,184,766, U.S. Pat. No. 5,560,535, U.S. Pat. No. 5,902,496, U.S. Pat. No. 6,173,881, U.S. Pat. No. 6,344,629 and U.S. Pat. No. 6,364,817, the disclosures of which are herein incorporated by reference. Such a framing gate changing system is used in the final assembly welding area of an automotive assembly line body shop to store and retrieve multiple body framing tools, commonly referred to as “gates”, so that multiple models or designs of vehicles bodies can be formed or framed on the same assembly line at a framing buck or framing station. At the framing station, major sheet metal body sub-assemblies are brought together and attached to each other by robotic welders to form a fully assembled body or framed assembly.
The sub-assemblies include a floor panel, body sides, cowl panel, header panels and other components which are positioned by devices such as clamping fixtures supported by the gates. As the framing process is performed at the framing station, the body geometry or fit of the major sub-assemblies is set by resistance welding the outer edge portions of the sub-assemblies to each other. Additional welds are commonly added downstream after the framing station to strengthen the connections further between the sub-assemblies. The additional welding process is commonly referred to as “re-spot”, but the process does not alter the body geometry established by the framer at the framing station.